re PR target/52692 ([avr]: Add support for avr-specific built-ins + LTO)

re PR target/52692 ([avr]: Add support for avr-specific built-ins + LTO)

gcc/
	PR target/52692
	* config/avr/avr.c (TARGET_BUILTIN_DECL): New define.
	(avr_builtin_decl): New static function.
	(struct avr_builtin_description, avr_bdesc): Move up.
	Add GTY marker. Add field fndecl. Remove redundant field id.
	(avr_init_builtins): Initialize avr_bdesc[ID].fndecl.
	(avr_expand_builtin): Code cleanup because .id is removed.

testsuite/
	PR target/52692
	* gcc.target/avr/torture/builtins-2.c: New test.

From-SVN: r185910